Refund for unused services and equipment

After being a loyal XFinity its customer for 15+ years I have cancelled my services. I went to a store in person. The customer service was lackluster. Now I see that XFinity is pending a full months charge on my account. If I only used 5 days of internet I feel strongly that XFinity should only charge me a partial months service. Do you offer that option in the case where a less than a week of the service & equipment was utilized? If you don’t offer partial charges in cases like mine (5 days out of 30 were active) then your company needs to consider that immediately. Verizon offers this. Also, why didn’t the customer service team at Bellingham’s store mention this to me? Seems odd. Please advise.