Bad service, no feedback

On 24 Apr I called M Sure to file a claim for a windscreen excess i paid to Glassfit. The guy i spoke to by the name of Patt gave me a reference number and asked me to send through the invoice of which i did. Same day he asked me to send through the mileage and i did exactly that. Last week, 2 May i sent an email following up on the progress of my claim and there was no response. Today i decide to call and a guy named Calvin told me the invoice cannot be accepted due to the fact that it's a handwritten invoice. My question was why was this not communicated to me on the day when my email came through? When was i gonna be told had i not called and followed up? When i asked him this he gave me such an attitude and i don't understand why because i'm a client and i have every right to ask those questions. I am not disputing the fact that i have to request a typed invoice BUT the manner in which this was communicated is extremely appalling. I don't know why you keep such people, people who don't know customer service, honestly.