Not allowed to buy on budget

I went to the PEP at Westwood to buy some stuff for my daughter's new place. I wanted to pay with my credit card over a period then the lady told me that they got an email to say that I can't buy on budget and it must go on straight. What bull is this and what email is she talking about. In the first place I hardly buy on credit at PEP and my credit card is up to date, who are they to tell me I must buy on straight and can't use my budget facility.