Paytm — Ordered size M delivered size L

Hi,
I ordered pair of briefs with size M on Paytm with order number [protected]. But the product delivered to me was size L. I asked them about the same and they asked me share the images. I shared the images with them. I didn't get any response from them. I tried to contact them through customer care contact number, but the call getting disconnected and same message being shared to contact through help and support through app.