How to remove digits from the end of dialed numbers

[kiwipython]

Hello,

We have a problem where users are calling word numbers with too many digits so the SIP trunk provider is rejecting the calls.
An example is 08007272265 (0800 SBS BANK). If the full number is entered into the app the call is rejected because it should be only 10 digits long. 0800727226.
I need a way to truncate any numbers starting with 0800 to be a total of 10 digits.
I have tried a few things without success. I suspect it can't be done but any suggestions will be appreciated,

Thanks

 

[TheodorosG_3CX]

Based on the provided example, the issue is related with digits that user put in the end of the dialed number.
Are they expect to dial at once also some kind of an IVR input?