Two doctors surgeries are scrapping their premium rate telephone numbers after being told by the government to reinstate numbers at the local rate.
GP practices have been told to stop using national rate phone lines
Dartford East Health Centre and Horsman's Place Surgery in Dartford introduced the 0870 numbers last year, despite complaints from patients.
The Kent practices are now writing to patients, informing them of the new number, at an estimated cost of £5,000.
Local Labour MP Dr Howard Stoate said a sensible number should have been used.
'Anxiety and worry'
"They should have taken patients' concerns seriously in the first place," he said.
In the government move, GP practices using national rate phone lines were told to switch to low rate numbers with effect from April.
Dr Stoate, who used to be a GP before he was elected as an MP, has led the campaign for the use of national rate numbers to be banned in local GP practices.
However, he pointed out on Tuesday that, as far as he was aware, some of the new numbers now being used were 0844, which were local rate business numbers but still chargeable.
Ringing an 0844 number can cost up to 5p a minute, which is 2p more than the standard daytime local call rate.
"I'm happy that things have got better, but the problem still has not gone away... I will be going to see the health minister to see what the next move is," he said.
He told BBC Radio Kent: "A lot of anxiety and worry could have been avoided if doctors had listened in the first place and gone for a number which was sensible."