Hi Howie, I believe that I have always had the mobile number and mostly an email too. I thought it had something to do with "required" information, but I could be wrong!
In any case I always ring the OTA at 8pm and tell them the guest is due sometime but I don't have an eta and that we close the office at 8.30pm and there is no one here to let them in. I suggest they contact the guest while I wait so that they know I mean business.
I also tell them that I want the ability for that guest to leave a review wiped. (depending on the reply!) {Obviously I also ask them to get the guest to contact me IF they are arriving tonight so we can make arrangements for the key.}
I also let them know that there wont be a refund should the guest ask as they have not:
1) read the terms on the website and
2) and not replied to the email that I sent them. So please don't call me back if the guest asks cos the answer will still be no.
I haven't had a complaint from any ota regarding the no refund and no review...yet!!