Nothing happens after 17.00 with out THE guy.

I bought a vacuum cleaner from Builders Kempton park a month ago. The vacuum is basically 2 parts, 1. The motor and wheels. ,(Back part) 2. The container that collects the dirt and dust, also the filters and the pipe connect to this part, ( front part). The vacuum cleaner front part got this flimsy clip that holds the front part to the back part. I only realised this on the second time I used the machine and thought it's not gonna hold. Well as I used the machine again the front part keeps coming off from the back part. I have taken it back to builders but what a mission it was.. I got to the shop 17:10. I asked for a refund and the lady phoned down to the person that needs to check the machine. She asked me to wait a bit as he is coming... After +- 20 Min the lady went to find the person but returned to say that he left already. She must book the machine in for repairs. I said I would rather prefer to have the refund as this is obviously a problem on the machines I would rather buy another make.... Then she started with a after 14day they can't refund only repair thing and the terms and conditions of the Builders return policy in writing behind the counter states 6 months.. Then Al of a sudden no manager or any staff members knew that this person only works till 17.00. Not 18.00 like every other staff member. So I am the only person that returned goods in the history of Builders Kempton park after 17.00! They tried to contact this person. But with no luck. The lady then got hold of the "Manufacturer" and wants to speak with me. . I refused to speak to them as I bought the appliance at Builders .. I have paid Builders for it. I have a Builders receipt. I even paid cash. 18.35 they decided to refund me with a voucher. They can.only do a voucher as the cashiers all left by now.. I have explained that I am starting work again the next day and can't collect this money as I can't just leave the work premises and pop back in again for security reasons. And when I leave work it is to late to collect. Well I have gave in on getting the voucher as it is late and i am the only customer left. Why was it such an issue if the policy reads 6 months... Why keep me then if they could have given me a refund before the cashiers left? Luckily the full amount was received from the voucher as I asked my friend to collect. I don't think i will ever support The Builders Group again..