Delivery delayed

Last week I was approved by BuyMondo for a contract phone under Mtn. I was asked to give a delivery aadress where the phone will be given and I used my work address but explained to the consultant that due to the covid pandemic I don't work full time. The consultant informed me that she would make a note for the driver to phone before hand to ask my whereabouts. To my surprise yesterday when a lady from Dsv called to verify my order, I was asked to go back to buymondo to change the work address as it would not correspond with the proof of residence I will provide them with. I was very shocked as I have been receiving stuff from Dsv at work and the proof of residence has never been an issue. I would always provide them with proof of res but my phones delivered at work, why are they doing this now, further delaying delivery of my phone?