I thought you were going to take it to the main dealers? - only they have the TSB information relating to this service bulletin and would of charged you the same or less for a diagnostic and the solution.
The flashing mileage issue is likely to be down to the CAN Bus due to the faulty bluetooth module. Because the bluetooth module is not working / offline it is causing some problems on the data bus. Replacing the module and a BSI reset will probably resolve both issues.
The part for the telephone interface unit has been replaced 3 times on the Bipper: 1613696780, item 30 below, cost £455.10 inc. VAT!
So if this is not an option, I would suggest that if you can get somebody with a Lexia and the S1279 module, that they could de-install the unit, which would at least stop the flashing.