Samsung — i am facing issue of very slow charging

Address:

Samsung Service Center ,Haveli Arcade , Gandhinagar ,Gujarat

I own samsung galaxy m30s, since last month i am facing issue of very slow charging even with original fast charger. I visited my nearest samsung service center at haveli arcade, gandhinagar, gujarat. But they are completely not interested to check my phone technically and repeatedly saying that its only bcoz of high temp.in summer only on other side i know that phone remains in ac room for 24 hrs all the day. They are not resolving my problem. Highly dissatisfying customer service.