How can I fix my Alex.Clark Co Mantle clock?

Hi and thanks.The problem is the westminster chimes are out of sequence: at the half hour it chimes the second quarter and third quarter instead of the first and second quarters;at the third quarter it chimes the second,third and first quarters (cedg) in that order;at the first quarter it chimes c e d g instead of e d c g;at the hour the chime is 4 then 1 (e c d g ) then 4 then 1 (e d c g ) .

Kind regards.

thomas