Vendor not registered in gst

Hi

we have doubt

we have sent one bill to finance team for process the payment one vendor name we care mediservices but they are not registered in gst and that thau have given their pan and cancelled chq copy in name of we care mediservices but out team have raise one quary that their sign in pan and invoice is not matching ...is that valid point to hold the payment taht vendor or should be match sign with invoice which have in pan .

please let me know .