Can you help

Hi I bought a fiat doblo carg van 56 plate from a dealer, and picked it up last saturday, I drove it home 10 miles and then parked at the house I then found a big black oil spill underneath, I moved the car to another spot and another oil leak appeared, the breaks were grinding also, I told the dealer and he said he would have a look at it, he put new pads and disks on it for me and said the oil leak was something to do with the auring? So got a part and said it was fixed, I picked up the van this morning and the same thing happened again but with clean oil this time, it was not residue or drops but quite a lot, I have took photos of the spills also, I kn ow have to take it back again:( and will probably have to wait another week until I get it back? The dealer gave me a 1 month parts and warrenty with the van, will I be able to ask for a new warranty for a month when it is fixed as I have not even driven it yet, just home and back to the garage twice, also he gave me van with 12 months mot, how can they pass the van with these faults? Should I contact vosa? Any advice would be appreciated, thanks stewart