This isn’t the way to address frustration with your employer
What you're supposed to do is send a polite email once per year, wait until the business goes bankrupt, watch the boss make off with millions, and never get any of your back-pay.
How is anyone expected to survive 5 months without pay? The flight charts are absolutely a safety critical item, and making pilots buy them without pay should be criminal. If an airline can't operate safely, then they shouldn't operate.
The pilot put no-one in danger by doing this.