Switching out of traiiling commission mutual funds at discount brokerages

Okay, I know the banks are not our friends, but this seriously takes the cake. Now that the CSA ban on certain mutual funds with trailing commissions is close to coming into effect, it appears the discount brokerages are refusing any further transactions into said mutual funds. Fair enough. I held RBF563 the RBC CANADIAN GOVT BOND INDEX FUND (which had trailing commissions) in a non-registered account, which I used to 'sweep' in any surplus funds after my ETFs DRIP'd each month, then when I collected enough money in that mutual fund to make paying a commission worthwhile, I would buy more of whichever ETF I needed to rebalance back to my intended asset allocation. Easy peasy. Tried to do that in March - no go, couldn't buy in to that mutual fund at all. So I figure, okay, switch that fund to another one being offered without a trailing fund. I found RBF5120, the PH&N CANADIAN MONEY MARKET FUND F SERIES which looks like it would work the same way (allow small monthly purchases). When I set it up to switch, I was a bit startled to find that RBF5120 would cost me a commission, but okay, it has no trailing fees so I guess that's the way it works now. I set up the fund switch transaction to take the commission out of the funds being switched. I look at it today, and I'm in a negative position in the account, because the switch specified a certain number of units, but in the one day to settle the switch, the fund dropped in value. Doesn't this seem wrong? If I set the switch transaction to occur on a certain day at a certain value, shouldn't that be what actually happens? How can the customer be penalized for the fund losing value in the one day to settle the transaction?