Problems setting up shipping table

[Kalmservices]

Hi
Domain Name: kalmservices.com

I am having problems setting up my shipping table configuration on OsCommerce, I am trying to get it to charge deliver by weight and have entered the values below. However, the resulting charge fluctuates and the fluctuation is very random. The items I sell are very heavy and it is important that the courier charges are transferred to the customer correctly.

For example: a product weighing 58 Kg should be charged (as I understand it) at £65.00 being over 50 Kg but not as much as 60 Kg. This is sometimes charged at £75.00 or £95.00 depending on how my computer feels on the day. I would be very grateful for anyone’s assistance.

This is the entry I have submitted: 3:2.99,6:6.99,9:9.99,12:14.50,15:16.60,17:18.50,20 :20.50,30:45.00,40:55.00,50:65.00,60:70.00,65:75.0 0,100:95.00,150:150.00

Best regards
Ken

www.kalmservices.com