So sorry about your situation. I don’t blame you for being upset, I’m upset for you!
I belong to the yahoo group This email address is being protected from spambots. You need JavaScript enabled to view it. They were very active at one time but still helpful, perhaps they could help.
Also Facebook has a group. I don’t do Facebook anymore.

Janet

You are right. The straight stitch on my 830 looks more like a stretch stitch than a straight stitch.
I made some samples a few weeks ago and took it in to be repaired.

I received a call yesterday saying it was ready. The repairman had replaced tension parts.
We drove right over. I tested it in the shop. The tension looks good, but the straight stitch still looks like a stretch stitch.
It looks really ugly sewn in reverse, or backwards (in directions I would need to sew in free motion stitching).

The shop manager and I looked at the new test sample together. .
I said, "I can't send a quilt to Paducah or Houston with stitching that looks like this."
She nodded yes in agreement.
She called the repairman, and came back saying, "He says he has done all he could do. He can't fix the straight stitch."

I said " Then it needs to go to the Bernina place in Chicago."
The shop manager refused. She was quite adamant.
She said I have to pay for the repair and then take my 830 back to the shop where I had originally purchased it and have that shop send it to Chicago.
I left it there. The repairman is supposed to call me Monday.

I am pretty upset. I want to be able to make a few competion quilts with free-motion quilting. I can't afford to buy a new machine. Does anyone have any suggestions?

Judy it sounds like your stitch is the stretch stitch. Have you checked the setting? Hope you have solved your problem.
I have the 830 and love it. Good luck. Janet
I have not had good luck with the titanium needles,

Help!
I haven't been able to get a good straight stitch on my Bernina 830.
The thread comes up on the left side of the needle hole, and goes down on the right side of the next needle hole. Instead of a good straight stitch, I get a modified zigzag stitch.
I use new Superior titanium Topstitch needles.
I am using the single hole throat plate.
The thread tension is balanced.

It doesn't bother me as much with piecing. However, I have been trying to use a variety of heavier weight threads for quilting stitches. to emphasize the quilting. I want the quilting to show. I am using top quality threads, but the thicker threads make the straight stitch look even worse.

Has anyone else had this problem?

Judy, in Virginia