Loop Mobile — says can't register card without last name

Dear Sir/ Madam, I had purchase a loop sim card from a distributor and when we sent the documents for verification the Loop people are saying that they can't register a sim without the last name. My issue is that as we don't use last name then how can we give our last name. We also submitted the documents like Adhar card and on the Adhar card the last name is not mentioned because we don't use last name. As Adhar card is today's big proof of Indian citizen and it cannot be wrong then how can't these people say that we can't register your card and they rejected our documents and now its been 3 weeks now and no call response from them. Distributor took our money and these people are not responding.Now if we don't have last name then should we stop using mobile. Please help!!!!!!!!!!