Extended Relieving Letter

Hello Sir\Madam, I need your valuable suggestion on my issue I have joined X Company in 23 Dec 2019 through contract of third party payroll. At the time of interview committed job position was different and when i was joined Org they gave me different responsibilities(i.e kind of intern). I keep requested to give my job responsibility as committed, they didnt care. finally i put down my resignation on Mar 11 2020. Neither payroll company nor Client company tried to talk to me to resolve the issue. After that Covid-19 affected & lockdown enforced in country. Because of Covid Job market got frozed and i didnt receive job calls for 7 months even though i keep updated my resume in job search portals. Now i found job, but i need extended relieving letter from Payroll company from 23 Dec 2019 to 23 Dec 2020. As discussed with them, they told me they will provide only from 23 Dec 2019 to 11 Mar 2020. My Confession to you: 1.As per Law, I know its not legal to ask extended relieving letter. Considering my future employment and my family condition. I need relieving letter. STRONG REASON: When i have completed interview process from client company, Payroll company ask me to resign from the existing employer(i.e previous company) & promised me they will give 8 LPA as package. Then i resigned from the company and was serving my notice. after 15 days they come back and said client company not approved the requested package i.e 8LPA. They can only offer 6.5LPA, at that time i was drawing salary closes to 6LPA from existing company. so i denied the offer, They told me they will try for 8LPA & asked me to relieve in 45days out of 60.They will pay 15 days amount, i have completed my notice period 45 days & i didnt get offer letter. Finally i relieved from company without job deducting 15 days salary in my full & final settlement(23 K). I asked them to provide other client interview, they didnt help me. Luckily client company approved 8LPA after 10days of my relieving(10 Dec 2019), then i joined the (23 Dec 2019). Now i have 9 months of Gap in my career & How do i proceed to get extended relieving letter.? Note: I know i have taken some stupid decision in my life, now i want to correct it. kindly suggest Regards, Raj