Shopping on line

In double eleven,i bought a set of soybean milk machine,this type of machine that i want to own it for a long time.In fact ,i have an old soybean milk machine,because it is used for a little long time,i want to change a new one.so i decide to buy a new one in double eleven.In previous day of double eleven i have added a soybean milk machine that type ,size and color was my favorite to cart,when the time is arriving i placed an order and paid,i wasn’t afraid that i can buy it,because the machine was today’s deal ,in usual day the machine was on 1200REM,but in this day the machine is 1000RMB,in this case,i can save 200RMB.
After two weeks i received it,i thought it met my requirement completely.then i attempted to make some fruit juice,it tasted very delicious and the fruit was cut very slim,my family all liked it.
Because i bought it by my cellphone,i didn’t give a good comment to them timely.About after three months i feedback it,if i gave a good comment to the machine i would get a returned 20RMB to my Alipay account ,added they didn’t give me an invoice for the deal ,they totally needed to returned 50RMB to me ,the customer service reply to me the time is too long,they couldn’t return 50RMB to me,when i saw this information i thought the shop wasn’t really in a good faith,i was angry with this matter and i want to complain to their supervisor about this matter.

I think I have reminded you about this before.  When you are talking about yourself it is "I" and not "i".