I am trying to build sentences in a formal and business context. Please help correct my errors. Thanks for any comments.

1. Through the introduction of XX Telecommunication Company, we have known that your company is one of the biggest manufacters of precise instruments in the UK. We are looking forward to establishing business relations with your company.

2.We have learnt that you produce pure-woolen sweaters for export. Due to our steady demand on this type of product, we wish you can sent price lists, catalogs and samples to us. We will reply once we receive them.

3.This is to inform you that we have received the ten cases of leather jackets from you. To our surprise, the specifications are inconsistent with your invoice. Obviously, you sent us the wrong products. Please email us about how to deal with them.

4.Performance management, reflecting a company's level of managing human resources, is a crucial part and difficult problem in human resource management. However at present, few companys can carefully consider whether their performance managements are effective or not.