I think whether you applied DIY or via a lawyer doesn't matter. When we called, we were asked the name, date and place of birth of the sponsor, then the agent came back double checking the address and email of the sponsor, the name of the applicant, phone number which we used to call the hotline. Then the agent located our file and informed us of the temp no. You can call the hotline by yourself.
Also, if you call, pls do it early. We started ringing at 9:03 am and waited for 20 min to get through.
Good luck!