Nissan Nash poor service

I have traded my vehicle in for a new model, yet I still get debited for my old vehicle even after having my new vehicle for 3 weeks, Nissan Nash had moved my debit order from the 7th of the month to the first putting me in bad debit as funds for the vehicle would only be available from the 7th of each month.

When contacting the dealer they left me to deal with this mess and now cannot help me until the first debit order goes off on the first which will bounce as funds will only be available from the 7th.