correct call spiel

English as a Second Language English Vocabulary, Grammar and Idioms
1

Please advice which one is correct. We are about to ask the caller if he called us before regarding his concern.

Is this the first time you are calling about this concern?

Is this the first time you call us about your concern?

Please feel free to share if you have further suggestion on the best way to say this.

Thanks a lot.

Hope you guys can help me within the day.

2

Hi,

I would use either:

Is this the first time you are calling about this concern? (As you have indicated) or

Is this the first time you have called us about your concern? (My suggestion)

Alan

3

Thank you so much. How about

Is this the first time you called us regarding your concern?

4

Hi, can you provide us explanation why the second one is correct?
I really appreciate all your help.