It should not be unless your comments on forum or trips in published section gets deleted or removed due to certain violation of terms and conditions of tripoto. And if its a technical glitch then please contact the customer support team of tripoto community. thank you
I saw your answer earlier on my query of credits for answering in forum decreased from 3 to 1, but sadly it's not there now. May be this is how your answers got deleted and your credits reduced. You can drop a mail to Tripoto.