Today I went to this chinese thai restaurant to treat my two friends who have birthdays close together and we had a good time. Food was good, service quick, etc

When I went to pay I thought I give them a tip £5 on a meal that costs £23 is quite good. The dumb chick almost mumbles a thank you and directs me where to put the tip and my friends was like 'you shuld have taken the cash back''. It ws the first time I had tipped and it will be the last, at a chinese restaurant anyways.

Anyways, has any1 stopped tipping after a similar incident or am I reading to much into this

Any replies will be appreciated