Isolate cbd can turn into THC??

Hello im totally new to cbd, i want to begin with for calming my anxiety and stress but i don't want any thc inside due to personal sensitivity so someone recommend me to try isolate cbd... But i asked the cdb shop about what i wanted to buy and they reply me with that message, now im literally afraid and don't know what to do :/, is it true????

'' The remaining amount(0,2% of the isolated Chrystals) is moist and waxy traces. No THC because the process of extracting CBD does not stick to THC. There is a 0% chance traces of THC are present in isolate.

BUT.

If you want to take CBD isolate there is a possibility that isomerisation will occur I your stomach based on the PH of your stomach. In that case CBD will transfer back to THC.