Client abuse from TheCourierGuy

I have an account with the courier guy and been using their services for more than a year but I recently came upon a very disturbing situation lately

My last shipment was booked on the 5th of December.

In the afternoon, I received an email that my account was in arrears after the shipment was collected.

I then logged into the system, saw that there was 3 boxes instead of 1 and made a deposit of R212 surcharge to clear it.

We received the parcel on the 6th of December and my account was cleared.

Today, the 12th December I received an email from Elvis Mkhari, one of their agents that my account is in arrears and I'm owing R2207.45 whereas I did not make any booking since the 5th December and somehow my last booking is now at R2600.

I then asked him why he was contacting me about a second surcharge 1 week later and what was the first surcharge for.

He proceeded to explain that he only saw their account today and the first surcharge was for 1 box not 3 boxes.

It is true that I booked with 1 box instead of 3 but when they charged me the surcharge on the 5th , they had already collected the 3 boxes. why will the surcharge apply for 1 box and the rest be charged 1 week later?

Note that this is not the first time I have paid a surcharge after collection but it cannot happen twice.

Additional cost applies when the dimensions and weight of the parcel collected does not match the one on the waybill.

After collection, they already had the right dimensions & weight and sent me an email to pay a surcharge which I did. Now what is the reason for a second surcharge?

This is simply unacceptable. I guess It was too soon to think that it was a decent courier service and imagine the audacity of the guy to threaten me with their attorneys for refusing to pay a second surcharge.

Big businesses been abusing small businesses because they have a powerful legal representation and can twist facts on their system