Tata Teleservices — Request for refund of payment of Account no.[protected]

Dear Sir/Madam,
We Basan equity broking limited[protected] using PRI line provided by Tata since 2018 as you can check every month I am paying PRI charges and as well as special rental scheme of 2.5K PM(EPBX charges). But last month my line was down so I complained to Tata and a technician visited my place and told me that the problem is of a EPBX and Tata will not solve the issue. But when I am paying 2500 every month then why Tata will not solve the issue. And after all this. My line was down for 12 to 15 days and afterwards I purchased the new EPBX box from a third party vendor and started my PRI Line. And When TATA is not providing the service then Tata should give me the refund which I paid previously.