'a request to produce new electronic device' - IELTS letter

I would appreciate if someone could do me huge favor and give some important comments. I thank you in advance.

Write a letter to a manufacturer to ask them to arrange production of a new item for you. Please say
- What item do you need?
- Why do you need it?

Dear Sir/Madam,

I am writing to request you to produce new electronic device for the Dick Smith electronic compay.
I would like to say that we need multi-functional latest computer for our company. I would appreciate it if you can design Dell computers and become long term supplier for us. We would be grateful for you if you could design them with fast operating system, high storage and compact size. Moreover, I would like say if you could print our logo and company name, it would be great advantage for us. In addition, I was wondering if you could manufacture 100 computers for next month as you know Christmas will be busy time of the year.

Admittedly, our last supplier supplied HP computers and we had many complaints from customers. They said gadgets were very slow and battery was major problem even though new computers' battery ran out under two hours. Therefore, we stopped dealing with them. We have heard a lot about your company image we would be pleased if you can help us in huge order. We want to reduce customer complaints and increase our sales, I would appreciate if you can produce them without these problems we had in HP.

I look forward to hearing from you about production of Dell computers. If you need any further information please contact me on +1111111. Thank you very much for your assistance.

Yours faithfully,
Roshan Panjabi

Moreover, I would like to say if you could print our logo and companys' name, it would be a great advantage for us.
-we had many complaints from the customers
-They said that gadgets were very slow and the power of the battery was the major problem
-these problems which we had in HP

I am writing to request you to produce new electronic device for the Dick Smith electronic compay.
I would like to say that we need multi-functional latest computer for our company. I would appreciate it if you can design Dell computers and become long term supplier for us. We would be grateful for you if you could design them with fast operating system, high storage and compact size. Moreover, I would to like say if you could print our logo and company name, it would be a great advantage for us. In addition, I was wondering if you could manufacture 100 computers for next month as you know Christmas will be busy time of the year.

Admittedly, our last supplier supplied HP computers and we had many complaints from the customers. They said that gadgets were very slow and the power of battery was major problem even though new computers' battery ran out under two hours. Therefore, we stopped dealing with them. We have heard a lot about your company image we would be pleased if you can help us in huge order. We want to reduce customer complaints and increase our sales, I would appreciate if you can produce them without these problems which we had in HP.

I look forward to hearing from you about production of Dell computers. If you need any further information please contact me on +1111111. Thank you very much for your assistance.

Yours faithfully,
Roshan Panjabi

Thanks very much Farina. I re-correct my mistakes. I would appreciate it if you add more comments on my letter.