Facing issues towards support from the author of Kartpul theme (TemplateMela)

I bought this theme on 2020-10-16 .

Initially we had issue which they fixed(after explaining thousand times). But recently we discovered that responsive version of theme is not working. So, I contacted theme support after renewing their support license. I reported responsive version issues & they replied me on speed issue which was not even reported. So, I created screen recordings to help them understand issues with all the details & in response they again asked for screen recording. I tried several times by creating screen recordings but they claimed that they fixed the issue. I can still see same issues. Only few of them were resolved. I do not understand how to explain issues now. I searched their company on internet & I found that they are from same country as me. So, I created screen recordings with audio in local language & still they don’t understand what is wrong. Or may be they are pretending. I am totally lost now. Please suggest me what should I do. This is their profile & they have ‘Power Elite Author’ badge.

There are several other buyers who complained about this author. Their themes are really poorly coded. Theme support is pathetic & tests your patience. Please suggest what should I do? I am lost.
Please help.