inconsistent and nonsensical calculation of delivery charges

last month I had an order delivered from Builders City branch, delivered to my flat at a charge of R65

this month I wanted to order wood, cut to size, I was advised I had to come into the store to give the measurements, but then I was charged a delivery of R270

had I ordered this wood online, I would have paid R130. Builders inform me its because I ordered the wood at the branch that I paid an extra R140, nowhere is written down as policy. And moreover, if this is policy, it is grossly nonsensical.

I will take my business to BUCO, where they atleast offer the option of free delivery