Any one can assist.

Looking to purchase a good quality international pre paid phone card have in the passed used..I TALK

But not having any luck locating phone shops that keep Pre Paid phone cards any more

ANY advise on best way to buy a plan or prepaid for 3 month stay in BKK to call Australia ????

I use the prefix 00500 to call UK, I find them as cheap as anyone. I know that does not directly answer your question, but I would take it into account anyway.

You can buy prepaid Phonenet cards from the Communications Authority of Thailand (CAT). Their office is on the west (river) side of Charoen Krung Road, between Suriwong and Siphraya Roads, in the parking lot of the Main Post Office. Note: this small portion of C.K. Road is one way northbound.

Going from memory on this part; normal office hours are approximately 8:30 a.m. - 8:00. p.m.Mon. - Fri,, and 8:30 a.m. - 4:30 p.m. Sat. and Sun. Presumably closed on Apr. 13 - 15 inclusive for Songkran.