Sorry to hear.
as per information in moi website, credit card become mandatory.
As far as i concerned even though our home country clear immigration there are chances you may face problem in qatar immigration.
Please may plan accordingly, as per my knowledge its better to postpon the ticket and apply for family visit visa. Or the traveller should get credit card and hotel reservation for one month free visit visa. Please may check following link moi for the requirement

(https://portal.moi.gov.qa/qatarvisas/visadetails.html?ctr=77&res=77).