Sendgrid email delivery drop due to Spamhaus listing

Starting on 2020-08-17, Sendgrid IP addresses were listed on Spamhaus for sending phishing emails. Shown here:

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This has dropped our email delivery to about 50%, as opposed to the usual 99%.

Is there anything I can do to resolve this, besides sending support tickets to Sendgrid or switching email providers?

To summarize, these are the options I could come up with:

1. Attempt to get the issues resolved through support. We've tried this, but they were very slow to respond, or responded with irrelevant/false information (e.g. claiming that they had gotten an IP address removed from Spamhaus, while they hadn't).
2. Get dedicated IP addresses. This would likely prevent blocks, as you have control over all emails sent, but does cost extra.
3. Switch to a different email provider.

I went with option 3 and switched to Mailgun, which was quite easy to set up and works very well so far. Of course, no provider is perfect, so if you want more peace of mind, go with option 2.