你可以用下面的句子来表达你没有收到退款的情况:

"I have not received a refund yet."
(我还没有收到退款。)

这句话的来源是英语中最基本的表达方式之一。"Refund" 指的是退款,"yet" 是个副词,意思是目前还没有发生。

下面是一些其他可以用来表达相同意思的句子:

"I have not received my refund."

(我还没有收到退款。)

"I have not received a refund for the amount I paid."

(我还没有收到所付款项的退款。)

"I have not received a refund as promised."

(我还没有收到承诺的退款。)