Manual Shipping


I’m having problems setting up my manual shipping rates. We have a courier contract and the rates look something like the following:

for consignments of 0 to 10 KGS there is a consignment charge of £8.20

for consignments of 10 to 20 KGS there is a consignment charge of £9.40

For these there is no per KG charge. So consignments of 4KGS and 9KGS would be £8.20 and 14KGS and 19KGS would be £9.40.

Above 20KGS there is a per kilo charge of £0.28 per kilo for each kilo above the 20KGS.

So for example a consigment of 29.7KGS should be = 9.4+(9.70.28)=£12.16

for some reason the cart is calculating it as £8.32

Using another, simpler, shipping method where we get a consignment charge of £9.1 for 0 to 10 KGS and then 0.72 per kilo above 10 kilos, should give for the 29.7KGS:

9.1 + (19.7
0.72) = £23.284

but cs cart is showing £21.38 which also makes no sense. I have no product-related charges and all the above are done just using the weight dependencies.

Many thanks for any guidance on this. I have a feeling I am missing something.