politeness - In customer settings, is it ok to ask for keigo to be repeated in more "normal" Japanese?

In the context of restaurants, convenience stores and similar situations, is it ok for a customer to ask for something that was said in keigo (or in manual keigo) to be repeated in more "normal" Japanese? Or would staff rather speak in English rather than non-keigo Japanese?

Assume the customer is not asking because they want to be more intimate, but because the customer (an obviously non-native speaker) hasn't learnt Japanese in its entirety yet.

Answer

Sure, that's fine. You could say 敬語{けいご}は難{むずか}しいので、タメ語{ご}でしゃべっていただけますか？ Although it's a bit funny when a beginner uses the word タメ語 because it's a bit slangy. But I can't think of a better way of saying it.

簡単{かんたん}な日本語{にほんご}でおねがいします should work well too (and has no slangs).