WARNING! THEY ARE OVERCARGING US!

I wish I could split my review in 2 sections. I have used The Courier Guy for a couple of years to send over a thousand parcels for my small bussiness. On the positive side they have delivered virtually all my parcels with only a few hickups and always good customer support. However, I now discovered that they have been overcharging me for the majority of my parcels. I make almost exclusive use of their lockers to drop my parcels so there is no ways that I can put a larger size parcel in the locker than what I booked. Also the items I send is light weight and the parcels are never over the weight limit. I exclusively use The Courier Guy boxes and flyers for packing my orders. I brought this under the attention of my local branch, they investigated and refunded some of it but now it's like pulling teeth. They never once appologized and also explicitly stated that they cannot guarentee that this trend of overcharging will not continue to happen in future. This is extremely frustrating because as a small business owner I need to be able to trust my courier company 100%. I cannot afford to spend so much time on checking up on them. I am so sad because I have recommended The Courier Guy to everyone I know. No I want to warn people to actually double check their invoices very carefully.