TCL — Company is rejecting to claim under warranty

I have requested service for the tv problem which occured i have lodged complain on29/08/2020 and then today 07/09/2020 they said that they have rejected to take my complaint under warranty so basically my tv had some display problems so the thing is the service provider said they display pannel should be replaced they said and they also said to wait for one week so that they will confirm me..and then later after 9 days i got to know that they have rejected my service and they were claiming that it is not in the warranty and they also said that the bill was also not correct and the later i asked them what to do now they said said the bill is improper so at the right moment i went to the showroom were i bought this tv and told everything about this so later they given me another copy of that which has more clarity without corrections because the previous bill was not accepted because the minor corrections so now all the corrections are corrected now in this another bill and then went to the servcice center and they said i will again upload the bill and lets see they said and they were not at all responsible for that they were saying that there is still no confirmation they said but after two days again they said it has been rejected wht is this all this nonsense it like really they people are mental harrasing me i use more 5 products of tcl on beliving that tcl is good trusted company but after this issue iam completely not gonna trust you and your products anymore i
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model number- tcl led 55 in (L551PUS)
BOUGHT DATE -02/04/2018
warranty validity- 3 years from bought date