Lack of customer service!!!

I bought a bicycle for my daughter's 4th birthday. It was enough that the bike was delivered late so I couldn't give my child a gift at her birthday party! The bike arrived on Tuesday, 01 March. 3 days after her party. After already disappointing a little girl on her birthday, I had to tell her on Tuesday that I have to send her bike back. Some nuts and bolts were missing as well as an instruction manual. The bike was eventually collected on that Friday, 04 March. Now besides all the rest, I haven't heard a single thing back from MRP Sport. I logged onto my husband's account (we bought the bike on his account) and lo and behold, the order we pick up on their is the one that states that the goods have been received and signed for. There is no update of the return and no sign of a new bike being sent. Now this might not mean much to MRP Sport, but I am fuming. I have had to disappoint my little girl not once, but twice and that upsets me. I need this sorted out ASAP and I need to know that the new bike I'm receiving gets delivered straight away and that it is guaranteed to be delivered in full, with every single nut & bolt and instruction manual so that I can set it up 100% for her.