You have made a blunder by signing a document and not keeping a copy of it, and then submitting an apology letter. You must have consulted elders in the family, competent and experienced well wishers, trained legal mind/lawyer/law firm in advance.
What was your designation and nature of duties in this telecom company? Were you guardian of some sensitive information and records in this company? Have you been charged for having taken out some sensitive documents, files? Which companies you have joined after leaving this company, and is it a near competitor? What is your current designation etc? Company can not restrict you to earn your livelihood.
It shall be appropriate to consult a competent and experienced service lawyer with all records, and communicate under expert guidance only.
Many a time’s companies flaunt such agreements to block the payment of wages to employees and/or extort the hard earned monies from employees. An ill informed employee falls into the legal traps and commits blunder. The employee should exercise enough caution and must consult before jumping to sign on the dotted line, and must keep copy of all docs on which he /she has signed.
Now you should build favorable record.
You have rightly observed that company did not declare that you shall be required to sign a confidentiality agreement. Moreover confidentiality was not part of the appointment letter and hence becomes an additional document, as company mentioned in offer letter that appointment letter shall be issued later. Having resigned from the previous job candidate has no option but to sign loads of all docs company put up to sign. However employee has the right to examine the docs, and can ask for a few days even. Company can circulate additional terms and conditions later after joining also but the employee has the option to submit humble dissent or decline to accept.
In your case you should submit that despite the fact you have been clamoring to get the certified copy of this confidentiality agreement by in person representations, but the same was never supplied to you.
You may submit a gentle representation in writing under proper acknowledgment addressed to good offices of your appointing authority, MD, CEO, Head-HR, Company Secretary and mention that company got confidentiality agreement, in addition to appointment letter, signed from you without granting an opportunity to get these examined properly and narrate the incidents in detail mentioning date, phone numbers, name/designation/dept. of concerned personnel/company name/address to whom you represented and their response that neither company nor their legal representative has supplied you the so called confidentiality agreement and the proofs confirming how you have violated the so called agreement and on the pretext of some imaginary violation payment of your earned wages has been willfully blocked by the company causing you financial and personal hardships. Company forced you to sign a drafted and printed apology letter. You may request the good offices to grant an appointment to you within next 2 days and meet you in person to clear your position, and provide you relief and supply by regd. post the payment of earned wages at once along with F&F statement, form-16, pf account details etc so as to reach you within say 7 days or you shall be constrained to lodge a complaint with lawful authority at the cost and consequences of the company. If the company is not supplying you, your PF number, and if you have demanded it in writing, company is committing an offence. You must demand PF accumulation reports in original. You must mention that you have not affected the business interest of the company and you are simply earning your livelihood by your education and experience.
If you are not able to resolve the situation on your own, you may have to proceed legally.
You are within your rights to lodge a complaint with o/o wages inspector.