What would you do if you receive a low-quality translator?

1. Make sure you revise the document(s) and files before starting a translation. Read all instructions that come with the job: they show you the way in which the translation must be approached. You wouldn’t call a plumber to repair a leak and leave your house without a shower. Ensure that all the files and documents that the client needs are the ones you have received.
2. Make sure that you are comfortable with the subject matter and language style and confirm this to the Translation Project Manager. Whilst you may take on translations in fields in which you are not an expert for the sake of expanding your business, it will take you more time to master the terminology and you will have to invest time in doing so. There is nothing wrong with it, but be aware that your own quality checking and revision become even more important. Sadly, there may be some subjects for which you are simply not qualified or that you are not good at. It is OK. Professional translators specialize in a few subjects and, in time, they become so good at them that they hardly take on anything outside their sphere of expertise.
3. Make sure you are familiar with the file format. If you are working for a translation company, the files should be sent in a translation-friendly format and with a translation memory. Do not change the CAT tool your client has specified. There is no worse feeling for Translation Project Managers than receiving a file that they have to re-structure because of bad formatting. You may have saved some money using a tool that promises full compatibility with this and that format, but if you have not tried it yourself and the original format is heavily formatted, you end up wasting the Project Manager’s precious time and ruining a good relationship. They will have to reconstruct the whole file and no matter how good your translation was, wasted time can never be recovered. You risk losing a client.
4. Use all reference materials, style guides, glossaries and terminology databases. Never ignore a glossary that has been sent to you. If the client has created a database, use it. If it is a simple excel file, you know all tools can import this format into a CAT tool and csv can create a glossary file in seconds. It is essential that you are consistent with the terminology and style of previous jobs. Quite often, you will not be the first translator involved in a publication process. One-time translation buyers are few and far between and if you want to succeed in business as a translator, you want regular, paying clients and a regular income. It may be the first time you are translating a particular piece or set of files. It may be the first time you are translating for a particular client, but they are sure to have bought translation services before and they expect consistency in style and terminology.

At that time, I relied on translation software and apologized to this person for working with us

It depends why it has happened and who the translator is, but generally - poor job - lower pay